A Variation in Acid-Catalyzed Isomerization of Abietadienoic Acids

摘要

Heating the individual common abietadienoic acid methyl esters withp-toluene sulfonic acid in chloroform led to the formation of methyl abietadienoates other than the equilibrium mixture of methyl abietate, palustrate, and neoabietate that is usually formed by acid-catalyzed isomerization. Of these other methyl abietadienoates, the three principal constituents comprised 10, 4 and 2 of the monomers; these compounds were isolated and identified as methyl 13#x3B2;-abieta-7,9(11)-dien-18-oate, methyl 7,9(11)-abietadien-18-oate, and methyl 8,12-abietadien-18-oate, respectively.